2007 Fiscal Year Final Research Report Summary
Regulation properties of glycolytic pathway in Toxoplasma gondii (enzyme property investigation)
| Project/Area Number |
17590376
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Parasitology (including Sanitary zoology)
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| Research Institution | Keio University |
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Principal Investigator |
TAKASHI Asai Keio University, School of Medicine, Assistant Professor (50175163)
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| Co-Investigator(Kenkyū-buntansha) |
MAEDA Takuya The University of Tokyo, The Institute of Medical Science, Research Associate (20383763)
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| Project Period (FY) |
2005 – 2007
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| Keywords | Glycolytic Pathway / Hexokinase / Pyruvate Kinase / Phosphoglucomutase / Parasitic Protozoa / Toxoplasma gondii / Mitochondria / Apicoplast |
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| Research Abstract |
A regulation mechanism of glycolytic pathway in Toxoplasma gondii is very simple. The initial product, glucose 6-phosphate, acts on an allosteric activator for pyruvate kinase and determines the flow rate. Other tentative key enzymes, hexokinase and phosphofructokinase, have no regulation properties. This is very surprising event because host organisms like human have very complicated some regulation mechanisms. In the process of this research, we have identified a novel pyruvate kinase whose physiological role is unknown. This enzyme use GDP as a substitute far ADP for the enzyme reaction. The pH optimal of this enzyme is in higher position and the enzyme is present in the mitochondrion and the apicoplast. There are no organisms except Toxoplasma gondii have the pyruvate kinase in mitochondrion up to date. A participation of this enzyme to the glycolytic pathway of Toxoplasma gondii is still unknown. The presence of this enzyme in the mitochondrion and the apicoplast has been extensively studied by using the some deletion mutants of N-terminal of this enzyme (J. Biol. Chem. in press). The physiological function of this enzyme is a future project to be solved. From the fact that glucose 6-phosphate is the most important substance for the glycolitic pathway of Toxoplasma gondii, we have made a recombinant protein for phosphoglucomutase that use glucose 6-phosphate as a substrate, and investigated some properties of phosphoglucomutase. Amino acid alignment analysis indicated that Toxoplasma gondii phosphoglucomutase was closely related to plant enzymes, and faraway to bacteria enzymes and closely related species, Plasmodium enzymes. There are no conspicuous properties in Toxoplasma gondii phosphoglucomutase but sensitiveness for the bivalent cation is quite different to other organism enzymes. We will report the properties of phosphoglucomutase in Toxoplasma gondii in the near future.
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[Journal Article] A NOVEL GDP-DEPENDENT PYRUVATE KINASE ISOZYME FROM Toxoplasma gondii, LOCALIZES TO BOTH THE APICOPLAST AND THE MITOCHONDRION2008
Author(s)
Tomoya, Saito, Manami, Nishi, Muoy, I., Lim, Bo, Wu, Takuya, Maeda, Hisayuki, Hashimoto, Tsutomu, Takeuchi, David, S., Roos, Takashi, Asai
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Journal Title
Description
「研究成果報告書概要(欧文)」より
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[Presentation] A confirmation of GDP-dependent pyruvate kinase isozyme(TgPykII)in its presentation at the mitochondrion and the apicoplast of Toxoplasma gondii2007
Author(s)
Saito, T, Nishi, M, Rim, MI, Takeuchi, T, Roos, DS, Asai, T
Organizer
The 6th Molecular Parasitology and Malarial
Place of Presentation
Matsuyama
Year and Date
20071028-29
Description
「研究成果報告書概要(欧文)」より
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[Presentation] トキソプラズマの糖代謝調節機構2006
Author(s)
浅井 隆志、斉藤 智也、前田 卓哉、竹内 勤
Organizer
第5回分子寄生虫、マラリア研究フォーラム
Place of Presentation
東京
Year and Date
20061028-29
Description
「研究成果報告書概要(和文)」より
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[Presentation] A novel GDP-dependent pyruvate kinase isozyme from Toxoplasma gondii is targeted to both the mitochondrion and the apicoplast2005
Author(s)
Saito, T, Maeda, T, Nishi, M, Roos, DS, Takeuchi, T, Asai, T
Organizer
XIIth International Congress on Toxoplasmosis
Place of Presentation
France
Year and Date
20050527-31
Description
「研究成果報告書概要(欧文)」より
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